Use shortcode to total two different fields wedding

// http://pastebin.com/kHpaHQvi originally
// http://www.gravityhelp.com/forums/topic/counter
// usage: [guests form=1] where 1 is the form ID
// from http://www.gravityhelp.com/forums/topic/counter#post-154024
add_shortcode('guests', 'total_guests');
function total_guests($atts) {
        $form_id = $atts['form'];

        // function to pull all the entries for one form
        $guests = RGFormsModel::get_leads($form_id);

        // start the totals at zero
        $adults = 0;
    $children = 0;

        // initialize a counter for the number of guests entries made
        $i = 0;

        // loop through all the returned results
        foreach ($guests as $amount) {
                // total the adults
                // change 2 here to the field ID which holds the number of adults
                $adults += $amount[2];

        // total the children
        // change 5 here to the field ID which holds the number of children
        $children += $amount[5];

                // increment the counter so we know how many total guess there are
                $i++; // we may not need to use this
        }
        // do some formatting and return the output from the shortcode
        $output = "So far $adults adults and $children kids are attending the wedding";

    // just the string above will be returned.
    // You can style it here or where you are using the shortcode
        return $output;
}
// needed for the above to process the guests list shortcode in sidebar widget
add_filter('widget_text', 'do_shortcode');